The present invention generally pertains to automated machinery, such as machines for cutting cloth and other sheet-type work materials, and is more particularly directed to a system for monitoring various operating parameters and providing a means for alerting an operator when preventive maintenance is required.
The present invention can be used with several different types of machine but has particular utility when used with machinery for performing cutting operations on a single ply or one or more layers of sheet-type work material stacked one-on-top-of-the-other. Accordingly, the present invention will be described herein as being directed to such use, however it should be noted that the present invention, in its broader aspects is not limited in this regard.
All machinery requires periodic preventive maintenance, however, the intervals between maintenance activities vary depending on the type and severity of the use to which the particular machine is subjected. Machinery for performing cutting operations on one or more layers of sheet-type work material, typically include a cutting head that carries a high speed reciprocating cutting blade. Generally the blade, and the mechanism for driving the blade are subjected to heavy loads.
The severity of these loads can vary, and as such, the frequency of scheduled preventive maintenance, e.g. lubrication of bearings, and sharpening of the blades should also vary accordingly. A difficulty that often occurs is that these machines do not include any system for alerting an operator to the necessity for preventive maintenance. Therefore, a periodic maintenance schedule is usually implemented wherein the maintenance operations are executed at predetermined regular intervals. The difficulty associated with this type of maintenance schedule is that no consideration is given to the severity, or lack thereof, of the conditions under which the machine is operating. Accordingly, maintenance operations are often performed before they are needed, unnecessarily taking the machine out of service and disrupting production schedules. Alternatively, the scheduled maintenance periods could be too infrequent, resulting in damage to the machine.
Based on the foregoing, it is the general object of the present invention to provide a means for determining when preventive maintenance on a machine is required, that overcomes the drawbacks of prior art methods for determining maintenance schedules.
It is a more specific object of the present invention to provide an apparatus for monitoring various machine operating parameters, comparing these parameters with stored data pertaining to machine wear, and alerting an operator when maintenance is required.
The present invention is directed to an apparatus for notifying machine operators of the necessity for preventive maintenance that includes means for inputting and storing difficulty factors corresponding to a level of machine, or component use at which preventive maintenance is required. Means are also provided for measuring various different machine operating parameters and for quantifying the measured operating parameters and proportionally adjusting the quantified operating parameters in comparison with the stored difficulty factors related to the severity of the machine operating conditions.
Once the proportionally adjusted operating parameters are established, they are accumulated via a summation means to determine the total accumulated machine usage since the last maintenance was performed on the machine. Once the total accumulated usage has been determined, means for comparing this data to the data corresponding to a maximum level or value of machine, or component use at which preventive maintenance is required are employed. When the means for comparing indicates that preventive maintenance is required, an indicator is energized to alert the operator. The indicator can also be set to alert the operator at a predetermined interval prior to the necessity for preventive maintenance, thereby allowing for a planned shutdown of the particular machine.
Preferably, the above-described apparatus will be used in conjunction with an apparatus for cutting pattern pieces from one or more layers of sheet-type work material having a cutter head and a reciprocating cutting blade. In this situation, the rate of reciprocation, the load on the motor, or some other operating parameter would be monitored by the measuring means and then proportionally adjusted by applying the appropriate difficulty factor corresponding to the severity of the use to which the machine is subjected. The indicator would then be energized once a predetermined accumulated usage level has been reached.
The present invention also resides in a method for notifying machine operators of the necessity for preventive maintenance wherein a sheet material cutting machine is provided that includes a movable cutter head for carrying a blade reciprocatingly mounted thereto and driven by a motor. A controller is associated with the sheet material cutting machine and has predetermined difficulty factors corresponding to the severity of cutting operations stored therein. In addition maximum values at which maintenance should be performed on the cutting machine are also stored in the controller.
During operation, it is preferable that the load on the motor and the duration of each use of the machine be measured. A difficulty factor is then assigned to each cutting operation performed by the cutting machine which quantifies the severity of the particular cutting operation. Next, the difficulty factor and the duration of each use are multiplied together to arrive at a product.
The products of each cutting machine use are then summed together to determine a total summed value which is then compared to the appropriate maximum value. Once the maximum value is reached, a warning preferably in the form of an indicator light is energized providing the machine operator with an indication for the need for maintenance to be performed on the machine.